On Wednesday 7 December, Ofgem approved P434 Half Hourly Settlement for UMS Metering Systems for implementation on 14 December 2022. The modification will ensure that all existing Non-Half Hourly (NHH) Unmetered Supplies (UMS) connections are required to move to Half Hourly (HH) settlement between October 2023 and October 2024.
This will be achieved through the existing Change of Measurement Class process, ahead of the move to Market-wide Half Hourly Settlement (MHHS) in October 2025. All new UMS connections would therefore need to be settled on a HH basis from October 2023. Ofgem approved P434 on the basis that it will promote the smooth transition of NHH UMS Metering System Identifiers (MSIDs) to HH settlement, delivering earlier MHHS benefits for UMS. The regulator added that the modification will promote effective competition in the generation and supply of electricity as the HH settlement data will be more accurate and granular, enabling more accurate purchasing, in turn promoting innovation and competition.